The present invention relates to the field of fuel injectors and fuel rails, and more particularly to reducing leaking in fuel rail and fuel injector assemblies.
Customer standards require that no fuel be spilled from a fuel rail/fuel injector interface when servicing a gasoline fuel system. The fuel system includes the fuel injector connected to the fuel rail, with both the fuel injector and the fuel rail containing relatively large volumes of liquid fuel. In the past, this requirement was achieved on MPI fuel systems by rigidly attaching the fuel injector to the fuel rail by means of a steel retaining clip. The steel retaining clips are designed so that under the worst case, such as an automobile collision, the fuel injector and the fuel rail would not become disconnected from one another, allowing fuel spillage.
However, with the new HPDI (High Pressure Direct Injection) system, the conditions for fuel system removal have greatly changed. A phenomenon known as xe2x80x9cinjector cokingxe2x80x9d occurs, which is found only in HPDI systems. This phenomenon is characterized by carbon deposits around the tip of the injector in the cylinder head. These deposits form a very strong bond between the injector and the cylinder head into which the injector is inserted, making removal of the injector from the cylinder head impossible, unless the carbon bond is broken first. In order to remove an injector that has been xe2x80x9ccokedxe2x80x9d into the cylinder head, the injector must first be disconnected from the fuel rail and then rotated approximately fifteen degrees to break the carbon bond. Upon breaking the carbon bond, the injector can easily be removed from the engine. However, once the injector is disconnected from the fuel rail, fuel can spill from either the fuel rail, the injector, or both, as there are no mechanisms in either the fuel rail or the injector to prevent such unwanted flow.
It would be beneficial to provide a fuel rail and/or a fuel injector that does not leak fuel or minimizes fuel leakage when the fuel rail and injector are disconnected from each other.
The present invention provides a fuel injector with a neck at an upstream end and a downstream end located at a distal end from the upstream end. A fuel channel extends from the upstream end to the downstream end and defines a substantially longitudinal axis. A check valve is located in the fuel channel proximate the upstream end.
The present invention also provides a fuel rail with a housing defining an opening having a substantially longitudinal axis passing therethrough. A one-way flow inhibitor is located in the opening.
The present invention provides for a method of reducing leaks when a fuel injector is removed from a housing. This method includes: providing a fuel channel in the fuel injector communicating with an opening in the housing; removing the fuel injector from the housing; biasing the first plunger against the first seat; and substantially retaining any unpressurized fuel in the fuel injector. The fuel channel of the fuel injector has a first check valve with a first plunger and a first seat.
The present invention also provides for another method of reducing leaks when a fuel injector is removed from a housing. This method includes: providing a fuel channel in the fuel injector communicating with an opening in the housing; removing the fuel injector from the housing; and substantially retaining any unpressurized fuel in the fuel injector. The fuel channel of the fuel injector has a first one-way flow inhibitor with a membrane extending across the fuel channel and a seal connecting the membrane of the fuel injector to a side wall of the fuel channel.